Principles of Proper Grazing
There is no better time than the present to think about doing things differently. With the increase in feed and fuel cost, it is more important than ever to keep inputs low. The largest
cost of livestock ownership is feed. The best way to reduce feed cost is to maximize what you already have. Many of our pastures are under-utilized, not because of the lack of inputs, but because of the lack of proper management.
What if you only had to feed hay for 30-60 days per year? What if you didn’t have to supplement your livestock with additional feed at all during the grazing period? What if you didn’t have to buy fertilizer to revive your pastures every spring? By following a few principles, we can dramatically improve our pastures, provide better forage for our livestock, and ultimately improve the longevity and profitability of our farms.
There are five principles that we can look to as a guide for our grazing management strategies:
1. Capture Sunlight:
If you are in the business of grazing livestock, then you are in the solar panel industry. You are using plants to harvest sunlight and create energy for your livestock. When the sun hits bare soil it is wasted.
2. Improve the water cycle:
Having healthy plant roots in the ground increases the absorption ability of the soil, decreasing runoff and increasing water filtration. This makes land less sensitive to drought and flood. If our pastures can store the rainfall rather than let it run off into the streams and rivers, then it can be used for dryer times.
3. Improve the Nutrient Cycle:
Just as we feed our livestock, we need to remember to feed our forages. We can do this by recycling nutrients from the soil back to the soil. Manure, saliva, and urine all add nutrients back to the soil.
4. Build Biology:
Biology starts with your livestock and the plants that they consume, but that is simply the tip of the iceberg. The microbiology (nematodes, worms, beetles, bacteria and fungi) beneath the surface are the real professionals. They help plants store, transport, and transfer nutrients. They are what keep the soil alive and functioning. In addition to the excrement from livestock, as plants are laid over and trampled by livestock, carbon is added back to the microorganisms in the soil.
5. Create a Polyculture:
Nature will always fight against a monoculture; it loves diversity. Weeds, or forbes, are actually a very natural and helpful plant. They strengthen and support the plants around them and many of the broadleaf plants provide an additional forage for livestock. Perhaps spraying or mowing down the non-competitive “pests” is actually hurting your main grazing forages.
In order to apply these grazing principles, there are a few terms that we must understand. The bare bones of a good grazing strategy is a large number of animals in a small area over a short period of time. Every farm has different context and resources, thus every grazing plan looks different, but all should abide by these principles.
Plants have three life stages. In stage one, a plant emerges using the energy stored in the root. In stage two, the plant uses sunlight to grow and develop large, leafy vegetation. It refills its energy “gas tank” in the roots which allows it to regrow many times in a season. In stage three, the plant matures and goes to seed. The goal is to graze plants in late stage two when they are big, green and leafy. This is most beneficial to both the plant and the animal grazing. Palatability and digestibility can be poor during stage three. Grazing in stage one stalls plant growth and root health.
Overgrazing occurs when the same plant is regrazed before it has time to recover. The rest period is arguably the most critical component of a grazing plan. You may utilize rotational grazing, but if you do not allow proper rest for forages, you can easily overgraze while still being “rotational.” Overgrazing can occur with one cow on 10 acres if access is not limited and areas rested. Moving animals off of an area that was grazed prevents the overgrazing of one plant by animals that selectively consume that plant at the same life cycle repeatedly.
Animal impact includes the impact of animal’s hooves on the soil as well as nutrients and biology livestock add back to the soil as they graze. Animals can be used to trample weeds and forage to add more litter or organic matter to the soil surface. Hooves can also be used to break open the soil surface to allow water to infiltrate. Too much animal impact in one area for an extended time is detrimental, but pulses of animal impact followed by rest is key.
This is how tightly the animals are bunched together while grazing. It is typically put in terms of pounds of animal per acre. A pasture that experiences a high stock density followed by rest allows better utilization of forage, better manure distribution, and prevents selective grazing. An ideal stocking density in Virginia would be a minimum of 50,000 lbs/acre. Some advanced grazing systems successfully graze at 500,000 lbs/acre.
Leaving plant litter on the ground helps to provide shade and shelter for organisms in the soil and adds carbon back to the soil. This cover on the ground also helps regulate soil temperature.